This Martin spider replaces Buna-N rubber spiders on Martin universal series (ML) or Martin super series (MS) jaw style flexible coupling assemblies and is made of nitrile rubber for transferring and absorbing shock load. This center element, also known as a spider, absorbs shock and misalignment within the coupling assembly for reduced wear on the shaft assembly. Martin jaw style couplings are suitable for use in various industrial power transmission applications, including compressors, blowers, pumps, conveyors, mixers, and gear boxes, among others. Flexible couplings are used to link two rotating shafts that are not aligned in order to transmit the rotational power, known as torque, from one shaft to the other. Most flexible couplings consist of two hubs and a middle assembly; each hub attaches to a shaft while the middle assembly flexes between the hubs to accommodate the misalignment of the two shafts. Shaft misalignments are generally either parallel or angular and cause complications to transmitting rotational power from one shaft to another in the form of stresses, loads, vibrations, and other forces, which vary from one type of misalignment to another. Flexible couplings are used in a broad range of applications, such as in motor vehicles, conveyors, escalators, agricultural, forestry and mining equipment, aeronautics, robotics and space exploration, among others.Martin Sprocket & Gear manufactures power transmission and conveying products. Martin provides tools that meet American National Standards Institute (ANSI), National Aerospace Standard (NAS), and Deutsches Institut für Normung (DIN) standards. The company, founded in 1951, is headquartered in Arlington, TX.